RPS alignment on blade

[[To...]]

Hello. Trying to help a customer out. They have a blade that supposedly is using 6 datum targets. 4 of them (X&Z) are pretty straight forward but 2 of them (Y) on the leading edge of the blade. Customer insists on using a curve at specified locations on the blades in order to find the highest point. He is also using Max Coordinate on the curve but I explained that will find the point with highest deviation. He claim that he has the Y axis selected under Datum and feels that should work. I suggested created a 2d line, in front the blade, recalling the points from the curve and then using Max coordinate on the line.

He is using a start alignment but due to the part not being so good, the curve has trouble finding the edge during the base alignment cycle. He has reversed the direction of the curve and not the curve makes it through the alignment but I don't believe he is getting the right data from using Max Coordinate from the curve.

Any suggestions? Customer could not provide me with any drawings or models, so I cannot provide to you.

[[Th...]]

Highest point as in most plus-material point along the curve?

[[To...]]

Please sign in to view this quote.

point on blade.jpg

[[Th...]]

Assuming they're looking for the coordinate of the blade peak then. Min/max coordinate constructions, when applied to curve features, report the point relative to a coordinate system axis. So if your customer establishes an alignment oriented to the part in that manner, then slaps the appropriate construction on and references the appropriate axis, they can get that point. I think this only applies to the curve's nominal points, so it won't fetch the inbetweens.

mpoint.JPGcurve.JPG

[[To...]]

What I find is when I use maximum coordinate on a curve, the result shows the point with the maximum deviation of the feature. In my example, point 1 happens to have the largest deviation of -.0033. I am surprised that it is a negative deviation but it is still the largest deviation. Note the actual location of point 1 in the curve and the location of the maximum coordinate are the same.

Screenshot 2021-03-05 155459.jpgScreenshot 2021-03-05 155601.jpg

[[To...]]

See desc from help file

max coordinate.jpg

[[To...]]

When I select Nominal Feature, the max coordinate does use point 7, which had the greatest positive deviation.

Screenshot 2021-03-05 161456.jpg

[[Th...]]

Here's what I found in the curve manual. Odd that your results seems to be the reverse of this.

curveconst.JPG

[[Ja...]]

What does it show you when you use axis as Datum instead of nominal feature?

[[Ri...]]

Can you run a theoretical plane thru the curve to get your intersection, and use that?

[[To...]]

Please sign in to view this quote.

As I mentioned earlier, when you use Nominal Feature, the derived point is the point with the most positive deviation. In my example, point 7 on my curve has .0030 plus deviation. When I select Datum and select Y, the derived point is the is the point with the greatest deviation, which is point 1 on my curve at -.0033 deviation. As I select other directions, X or Z, I don't ever see a point at the tip or end of the curve.

Mind you, I am doing this in simulation with dispersion active.

[[To...]]

Please sign in to view this quote.

Thomas, Thank you. My original search did not take me to that page in the help. My customer was using max point and I made the mistake of using max point, too, but my test was using a curve in the -Y direction. When I selected minimum point, and Datum Y, the point is exactly where I wanted it to be. In my test, when I used max point, it just happened that the most +Y point in my curve had the greatest deviation (-.0033), so it was leading me down the wrong path.

Again thanks for the guidance.

[[SH...]]

I have seen a zeiss webinar, in which the Zeiss engineer directly extract the datum target from the cad model using the extract feature option in the cad menu.